Height adjustable tilting device for rev olving chairs



HEIGHT ADJUSTABLE TILTING DEVICE FOR REVOLVING CHAIRS Filed Aug. 14, 1962 C. H. M. BERNARD May 25, 1965 2 Sheets-Sheet 1 hm E. sglwo-b May 25, 1965 C. H. M- BERNARD 2 Sheets-Sheet 2 Filed Aug. 14, 1962 a y 2% -l a w M Am :I -m\ \M/IC IMWWfi IIIIZ I l 7 m p. B .p M a m wzw ww mww zzfl mu 5 I I A 2 M a United States Patent 3,185,430 HEIGHT ADJUSTABLE TILTING DEVICE FOR REVOLVING CHAIRS Charles Henri Marius Bernard, 87 Ave. de Wagram, Paris 17, France Filed Aug. 14, 1962, Ser. No. 216,855 2 Claims. (Cl. 248-381) The present invention relates to a revolving device, adjustable for height and for tilting according to the weight of the user; particularly for olfice chairs.

Various other characteristics of theyinvention will be revealed by the detailed description Which follows.

One preferred embodiment of the invention is shown by way of example in the attached drawings.

FIGURE 1 is a front view of the pivoting device, adjustable for height, for chairs.

FIGURE 2 is a section along the line IIII of FIG. 1.

FIGURE 3 is a section showing the device in the tilted position.

FIGURE 4 is a plane view of the upper part of the device.

In FIGURE 1, the device is formed by a vertical shaft 1 comprising at its upper end a bracket 2, having a hole. 3 therein.

The lower end of shaft 1 is closed by a plug 5 secured by four screws placed at 90 to each other (only two, 6 and 7, are visible in the drawing), located at the lower end of shaft 1. i

A threaded rod 8 is rigidly fixed in the plug 5 and is screwed into a cap 8a having a threaded bore 8b. The lower part 9, or base, of the device, formed by a casting of light alloy, for example, internally contains a bushing 9a in which the rod 8 can rotate freely without wearing out the lower part 9. At its upper end, the bushing 9a comprises a collar 9b forming an abutment for screws 10 in the cap 8a. A ball bearing 11 is interposed between the upper end of the bushing 9a and the bottom of the cap 8a. When the shaft 1 is to be raised, the cap 8a is screwed clockwise or the chair is rotated counterclocle wise while holding the cap. In the opposite direction, if the shaft 1 is to be lowered, the cap 8a is rotated counterclockwise or the chair is turned in the clockwise direction, again holding the cap.

The ball bearing 11 enables the chair to be rotated in relation to the lower part without altering the height of the chair.

An aperture 12 is made in the upper part of the shaft 1, through which bushing 18 becomes accessible for adjusting of a spring 13.

The spring 13 is placed inside the shaft 1 and is held, at its lower part, by a washer 14 having a hemispherical cavity 15 cooperating with a part of corresponding ball shape 16 on the lower end of a rod 17. The latter, which goes through bushing 18 screwed into the upper end of the shaft, forming an abutment for the spring 13, has, at its upper end, a spherical washer 19 which abuts against a nut 20 screwed on the threaded upper art 17a of the rod 17. The bushing 18 has a plurality of holes 18:: near its lower end.

A plate 21 has in its center a conical hole 22 for receiving the washer 19. The hole 22 has two small diametrically opposed extensions 22a, 22b. The plate 21 has two brackets 24, 25 rotatablyconnected by means 3,185,430 Patented May 25, 1965 ice of an horizontal shaft 26 with the bracket 2 of the shaft 1. The seat 27 of the chair is fixed on the plate 21.

When the user wants to tilt his chair to the rear, he presses on the rear part of the seat, whereby the rod 17 is pulled upwards, as shown in FIGURE 3. Thereby the spring 13 is compressed until the coils of the spring 13 are ahnost contacting one another, the spring becoming compressed almost to its solid height.

The return to the horizontal position is caused by the force of spring 13, as soon as the user ceases to exert pressure on the rear of the seat. The spring 13 returns the various components to the original position as shown in FIGURES 1 and 2.

The bushing 18 having the holes 18a which are accessible through the opening 12 serves the purpose of compressing the spring 13 at will, thus providing for a more or less greater resistance to the pull of the rod 17. This device enables the tilting of the chair to be controlled in relation to the weight of its user.

In certain cases, the rotating device may be constructed in such manner that the seat of the chair pivots forward, whereby the linkage formed by the brackets 2, 24, 25 and by the shaft 26 is placed under the front of the seat of the chair.

The device described above is easy to manufacture, very strong on account of its simplicity and sufficiently aesthetic for an oflice chair. Generally speaking, the pivoting and tilting components of the device are made of suitable metals or plastic materials.

Various modifications may be applied to the preferred embodiment, as shown and described in detail, without going beyond the scope of the invention.

I claim:

1. A revolving device, adjustable for height and for tilting according to the weight of the user, for chairs, particularly for office chairs, having a base and a plate, having a conical hole in the center thereof, comprising: a horizontal shaft on said plate, a vertical shaft, a first threaded rod rigidly pxed on said vertical shaft, a cap having a threaded bore, said cap being rotatably arranged on said base, said threaded rod fitted into said bore in said cap, a spring located in said vertical shaft, said spring resting on an abutment in said vertical shaft, a second rod located inside said spring, said rod having a semi-spherical end, a first spring washer having a semi-spherical cavity into which said semi-spherical end of said second rod is fitted, a spherical washer adjustably screwed on the upper end of said second rod, said spherical washer being seated in said conical hole of said plate and a ball-bearing on said base, said ball-bearing supporting said cap.

2. A revolving device according to claim 1, and having an adjustable, threaded bushing in said vertical shaft, said bushing having an abutment for holding said spring.

References Cited by the Examiner UNITED STATES PATENTS 1,346,110 7/20 Atwood 248-679 1,755,228 4/30 Stoll 248-388 1,873,054 8/ 32 Sheldrick 248-380 2,689,599 9/ 54 Mauser 248-378 X CLAUDE A. LE ROY, Primary Examiner.

FRANK L. ABBOTT, Examiner. 

1. REVOLVING DEVICE, ADJUSTABLE FOR HEIGHT AND FOR TILTING ACCORDING TO THE WEIGHT OF THE USER, FOR CHAIRS, PARTICULARLY OF OFFICE CHAIRS, HAVING A BASE AND A PLATE, HAVING A CONICAL HOLE IN THE CENTER THEREOF, COMPRISING: A HORIZONTAL SHAFT ON SAID PLATE, VERTICAL SHAFT, A FIRST THREADED ROD RIGIDLY PIXED ON SAID VERTICAL SHAFT A CAP HAVING A THREADED BORE, SAID CAP BEING ROTATABLY ARRANGED ON SAID BASE, SAID THREADED ROD FITTED INTO SAID BORE IN SAID CAP, A SPRING LOCATED IN SAID VERTICAL SHAFT, SAID SPRING RESTING ON AN ABUTMENT IN SAID VERTICAL SHAFT, A SECOND ROD LOCATED INSIDE SAID SPRING, SAID ROD HAVING A SEMI-SPHERICAL END, A FIRST SPRING WASHER HAVING A SEMI-SPHERICAL CAVITY INTO WHICH SAID SEMI-SPHERICAL END OF SAID SECOND ROD IS FITTED, A SPHERICAL WASHER ADJUSTABLY SCREWED ON THE UPPER END OF SAID SECOND ROD, SAID SPHERICAL WASHER BEING SEATED IN SAID CONICAL HOLE OF SAID PLATE AND A BALL-BEARING ON SAID BASE, SAID BALL-BEARING SUPPORTING SAID CAP. 